Abstract
Motivated by the newly synthesized mixed-valent spinel for which a large thermopower is observed in the metallic cubic phase above 230 K [Y. Okamoto et al., Phys. Rev. Lett. 101, 086404 (2008)], we calculate the Seebeck coefficient by the combination of local density approximation and dynamical mean-field theory . The experimental values are well reproduced not only by but also by the less involved Boltzmann equation approach. A careful analysis of the latter shows unexpectedly that the origin of the large thermopower shares a common root with a very different oxide: . We also discuss how it is possible to further increase the power factor of through doping, which makes the material even more promising for technological applications.
- Received 3 June 2008
DOI:https://doi.org/10.1103/PhysRevB.78.115121
©2008 American Physical Society